Laser welding is a widely used commercial process in which a laser beam irradiates a targeted area of a work stack. Electron beams may be used in a similar manner. The irradiated material changes to a liquefied state due to the intensity of the laser beam. A fusion spot weld or weld seam results when the liquefied material cools. Beam welding can be used to effectively form a fusion weld completely through the thickness of a pair of adjacent sheets in a typical two-sheet work stack. However, suboptimal fusion welds may result when attempting to beam weld a work stack having three or more sheets, especially for dissimilar materials.